Manufacture of knitted brief blanks

ABSTRACT

A method of knitting side-by-side brief blanks (BLK, BLK&#39;) in the form of a tube (T) on an electronically controlled circular knitting machine wherein the tube (T) is shaped by needle selection (50) between the brief blanks (BLK, BLK&#39;) to form apertures (AP, AP&#39;) which provide leg openings (LO, LO&#39;) by taking out of action needles (50&#39;) which would otherwise knit yarn across the apertures (AP, AP&#39;). At the same time yarn feed (Y2) to the inoperative needles (50&#39;) is cut (42, 44) and trapped (46) whereby the apertures (AP, AP&#39;) are formed. End portions of the blanks (BLK, BLK&#39;) remain interconnected until the tube (T) is slit walewise to provide separate blanks (BLK, BLK&#39;) for making up briefs. Since yarn is not knitted across the apertures (AP, AP&#39;), a considerable saving in the use of yarn is effected whilst shaping of leg openings (LO, LO&#39;) is facilitated.

The present invention relates to the manufacture of knitted brief blanksfrom which briefs are produced.

By briefs is meant a garment comprising a body portion adapted to coverthe lower portion of a wearers trunk from the waist downwards to andbeneath the crotch, and having therein two leg openings at respectivelyopposite sides of the crotch portion which closes the garment at itslower end.

Traditionally, knitted briefs were manufactured by a process known ascutting and sewing in which a blank of the shape illustrated in FIG. 1of British patent no. 1 485 952 was cut manually from flat knittedfabric. The blank was then side seamed into a brief proper. Clearly thisprocess was time consuming and thus expensive.

The invention disclosed in British patent no. 1 485 952 represented asignificant step forward in that a brief blank of the required form wasproduced from a seamless tubular blank on a circular knitting machine.This tubular blank was then slit, flattened and side-seamed.

European patent no. 0 211 641 provided a further step forward in that itenabled a row of brief blanks to be knitted in the form of a tube whichblanks were interconnected in side-by-side relationship. FIG. 5 of theEuropean patent illustrates an unslit waisted tube having walewiseseparation positions 22 which, when slit, provides two brief blanks forside seaming into briefs proper.

The method described in the European patent has worked well commerciallysave that, especially when three or more blanks have been knitted in arow, when walewise separation has been effected there has been atendency for the crotch portion not to shrink sufficiently laterallybetween the points AC and A1-C1 as viewed in FIG. 2. This has meant thatit has been necessary for an operator to cut away fabric between thelines A-A1 and C-C1 which is clearly undesirable since it slows downproduction. Even when only two blanks have been produced it hasoccasionally been necessary to cut away fabric as described above.

The present invention seeks to reduce the amount of yarn wasted inknitting a blank, more especially a brief blank, when knitted as one ofa row of blanks as described in European patent no. 0 211 641.

In accordance with the present invention there is provided a method ofknitting a plurality of brief blanks in a row in side-by-siderelationship in the form of a tube, which method comprises knitting asaid tube on an electronically controlled circular knitting machinehaving full electro-mechanical needle to needle selection and stitchlength control, and comprising the steps of shaping by needle selectionthe tube at positions between brief blanks more especially to formapertures which are to provide leg openings by taking out of actionneedles which would otherwise knit yarn across said apertures whilstsimultaneously cutting and trapping yarn fed to said inoperative needleswhereby said apertures are formed between brief blanks with end portionsof the latter remaining interconnected, and slitting the tube walewiseat positions between said blanks to provide a plurality of separatebrief blanks of the required form for brief manufacture.

One advantage of the present invention is that it enables the amount ofyarn wasted by cut loss in the method of European patent number 0 211641 to be reduced by 15 to 20% dependent upon the number of brief blanksproduced in a row.

A further advantage of the invention is that the shaping of the legopening is facilitated considerably enabling each blank to be shaped andstyled for a particular end use, e.g. fashion, sports or medicalapplications. In this connection it will be seen that different types ofbriefs, e.g. a sports brief and a fashion brief can be produced in thesame row of a tube.

The invention will now be described further by way of example withreference to the accompanying drawings in which:

FIG. 1 shows, in diagrammatic form, an unslit waisted tube as taken downfrom a circular knitting machine;

FIG. 2 shows an opened out flat knitted brief blank produced from theknitted tube shown in FIG. 1;

FIG. 3 illustrates one of the blanks, shown in FIG. 2 folded over intobrief form ready for seaming;

FIG. 4 illustrates briefs completed from the folded over blank of FIG.3;

FIG. 5 illustrates a modified unslit waisted tube of FIG. 1 turnedthrough a right angle;

FIGS. 6 and 7 illustrates diagrammatically a method of performing theinvention using a yarn cutter and trapper, and

FIG. 8 is a perspective view showing the arrangement of FIG. 6 and 7applied in practice to a multi-feed circular knitting machine.

The waisted tube T shown in FIG. 1 is knitted by wholly rotary knittingon an electronically controlled multi-feed circular knitting machine.The tube T consists of two overlaid and connected brief blanks BLK andBLK' and is of generally hour glass form after removal from the machine.

An aperture AP is shown as elongate and generally parallel sided. Itwill be appreciated that the shape is for ease of illustration onlysince, in practice, the aperture is wider at its centre than at its endsas may be seen from FIG. 5. The aperture AP has a "shaping fringe" SFformed between DS-CS-CS-DS-D1-C1-C-D and, at that side provides legopenings LO, LO' respectively one to each blank BLK, BLK'. Similarly atthe other or right side a further aperture AP' having a "shaping fringe"SF' extend between BS-AS-AS-BS-B1-A1-A1-B and provides a further legopening LO or LO' to each blank. The crotch portion is shown between Gand G1.

The blanks BLK, BLK' are connected at their ends E-D, DS and F-D1, DS,and also at E1-B, BS and F1-B1, BS. The portions E-E1 and F-F1 of thefront brief blank BLK will form the waistband WB of a brief producedfrom that blank, the same arrangement applying to the rear brief blankBLK'. In order to facilitate separation of the two brief blanks a numberof needles of the machine, e.g., three, are omitted at diametricallyopposite portions of the tube T as indicated at Z--Z in a known manner.

Forming of the apertures AP, AP' during knitting avoids the considerablewastage of yarn that would otherwise have been knitted across theapertures AP, AP' and then subsequently removed, as well as dispensingwith the removal operation.

Referring to FIGS. 6 and 7 there is shown diagrammatically part of acircular knitting machine in which a yarn feeder is indicated at 40having a feeder arm 41, an upper fixed yarn cutter or knife at 42, ayarn transporter and rotary lower cutter at 44 and a yarn trappingdevice at 46.

Although the cutter 42 is in a fixed position in relation to the rotarycutter 44, it is spring loaded at 48 against the face of the latter atthe peripheral teeth 440 for an effective cutting action. The cutter 44is a ring of flat circular saw tooth form and is rotationally fast withthe needle cylinder 55 of the machine. The teeth 440 are of ratchet orbuttress form to each provide a cutting edge 442 for edgewiseco-operation with the fixed cutter 42.

Yarn is designated Y1 to the feeder arm 41, at Y2 from the feeder arm 41to selected needles 50, and at Y3 away from the cutters 42, 44. Theneedle selecting system being known is not shown.

As the needle cylinder 55 rotates individual needles 50 are selected atthe position S1 (FIG. 6). The selected needles 50 are raised by theneedle cam actuation means in a known manner to clear the old orpreviously knitted loops and position the needles to receive yarn Y2from the feeder arm 41 to enable new or further loops to be formed. Thisknitting action continues for a group or number of selected needles 50.

When the last needle of a selected group of needles is reached andpasses the feeder arm 41, subsequent needles 50' remain at a lower orinoperative level as shown in FIG. 7 and so simply pass by the arm 41.Yarn feed Y2 from the feeder arm 41 then passes over the inoperativeneedles 50' inwards towards the centre of the machine knitting head and,in so doing, is caught in the teeth 440 of the transporter/cutter 44 asit rotates with the needle cylinder 55 at the same speed as the latter.In FIG. 7 the yarn Y2 is shown caught by a tooth 440 just prior to beingcut and is also shown already initially drawn at Y2' into the suctionnozzle 460.

The caught yarn is then scissored by the action of the rotary cutter 44and the fixed cutter 42. This action produces two loose yarn ends, oneat and with the end of the group of selected needles at Y3 i.e., awayfrom the cutters 42, 44 and the other Y2' from the feeder arm 41. Thisend Y2' is retained by the suction action of the trapping device 46 inthe nozzle 460 and suction tube 461 of the latter.

When the leading needle of the next selected group of needles 50 reachesthe yarn end Y2' from the feeder arm 41, it collects the yarn end in theleading needle hook and takes the yarn into a knitting action at theknitting point S2 adjacent the arm 41 by withdrawing the yarn end Y2'from the trapping device 46. The following selected needles 50 thencontinue the knitting action. Having regard to the speed of rotation ofthe needle cylinder 55 and of the operation of the machine, eachabove-mentioned yarn end Y2' is only very momentarily received in thesuction trapping device 46. The suction device 46 also serves to removeany minor fragments of yarn and fluff in the vicinity of the yarn feederarm 41 and needles 50, 50'.

In FIG. 8 a practical form of the yarn feeding, cutting and trappingarrangement or station on a multi-feed circular knitting machine isshown in which the feeder arm 41, or each such arm of the yarn feeder40, is raised for yarn take up by a selected group of needles 50 orlowered (as shown) when inoperative needles 50' are passing the feederarm 41. For this purpose the arm 41 is pivoted in the body 400 of theyarn feeder 40 and operated by a solenoid 45 or other suitable actuatorcontrolled by the electronic system of the machine.

Yarn Y1 is guided at 43 to the feeder arm 41 and also to other arms 41'of the feeder 40, which arms 41' are shown in an inoperative positionwith their yarn Y4 held by a blade or plate 47 carried by the suctionnozzle 460 in readiness for use when required.

The fixed cutter 42 is shown spring loaded at 48 against the rotarycutter 44 and a pressurised air supply pipe is provided at 49 forblowing away small pieces of yarn and fluff from the cutting area.

Although not visible yarn Y2' from the feeder arm 41 enters the suctionnozzle 460 but is shown extending from the latter to the fixed cutter 42where it is about to be cut prior to being instantly and fully drawninto the nozzle 460. The cut end Y3 (FIG. 7) moves away in engagementwith retracted needles 50' as the latter travel away from the fixedcutter 42, which needles follow the end of a previously selected group.

The two "loose yarn ends" one Y3 following at the end of a selectedneedle knitting group and the other Y2' at the beginning of the nextselected needle knitting group produce the "shaping fringe" SF or SF1(FIGS. 1, 2 and 5), each yarn end being approximately 15 mm long. The"shaping fringe" is removed during the making up operation andconstitutes the only waste material produced.

After the knitted tube lengths T have been produced they are relaxed,normally by tumbling. Walewise separation then occurs along the walewiseseparation portions W (FIG. 5). In the making up operation, best seen inFIGS. 2 to 4, the edges which will form the leg openings LO, are trimmedor machined to elasticate and/or attach lace fabric for decoration.These processes remove the "shaping fringes" SF, SF' as referred toabove.

Each individual blank BLK or BLK' such as the blank BLK (FIG. 2) is thenfolded as shown in FIG. 3 face to face inwardly and the side seams aremade to complete the briefs', shown in FIG. 4.

The briefs are then finalised in bulk and are given finishing treatmentsas required, i.e. dyeing etc. The individual briefs are then turnedinside out, inspected, folded and packed as required.

It will be apparent that whereas in the described embodiment two briefblanks are provided in a row in side-by-side relationship, in practice,more than two blanks may be knitted in a row, the actual numberdepending upon both the size of the briefs required and that of themachine diameter.

EXAMPLE OF KNITTING MACHINE

A tubular length of fabric as illustrated in FIG. 5 was knitted upon a13 inch diameter, 28 gauge, 1152 needles, 4 feeds, 150/120 rev/mincircular knitting machine. The machine had fully programmable unlimitedelectro-mechanical needle selection and stitch length control. A yarncutting and trapping system was provided at each knitting point. Thefour feeding stations were arranged about the needle cylinder in anequi-spaced manner corresponding to the knitting points.

What is claimed is:
 1. A method of forming a plurality of brief blankson a circular knitting machine having needle selection and stitch lengthcontrol, the method comprising the steps of:forming a tube of briefblanks in a side-by-side relationship; forming apertures at positionsbetween the brief blanks as leg openings by taking needles out of actionto cause the needles to be inoperative; cutting and trapping yarn feedto the inoperative needles; and slitting the tube walewise at positionsbetween the blanks to provide a plurality of separate brief blanks forbrief manufacture.
 2. The method of forming a plurality of brief blanksaccording to claim 1, wherein the yarn feed is cut and trapped after thepassage of a group of selected operative needles past the point of theyarn feed in readiness for taking up the trapped yarn by a next group ofoperative needles and following the passage of said inoperative needles.3. The method of forming a plurality of brief blanks according to claim1, wherein yarn feed to the inoperative needles is cut by a fixed cutterco-operating with a rotary toothed cutter rotatable with the needlecylinder of the knitting machine which rotary toothed cutter also servesto catch said yarn feed for said cutting.
 4. The method of forming aplurality of brief blanks according to claim 1, wherein the yarn feed tothe inoperative needles is trapped by means of a suction device.
 5. Themethod of forming a plurality of brief blanks according to claim 3,wherein the fixed cutter is spring loaded against a face part of therotary toothed cutter containing the cutter teeth thereof for obtainingan effective yarn cutting action.
 6. A method of forming a plurality ofbrief blanks on an electronically controlled circular knitting machinehaving full electro-mechanical needle to needle selection and stitchlength control, comprising the steps of:forming a tube of brief blanksin a side-by-side relationship; forming apertures at positions betweenthe brief blanks as leg openings by taking needles out of action tocause the needles to be inoperative; simultaneously cutting and trappingyarn feed to the inoperative needles for forming apertures between briefblanks with end portions of the brief blanks remaining interconnected,and slitting the tube walewise at positions between the blanks toprovide a plurality of separate brief blanks for brief manufacture. 7.The method of knitting a plurality of brief blanks according to claim 6,wherein the yarn feed is cut and trapped after the passage of a group ofselected operative needles past the point of said yarn feed in readinessfor taking up the trapped yarn by a next group of operative needles andfollowing the passage of said inoperative needles.
 8. The method ofknitting a plurality of brief blanks according to claim 6, wherein yarnfeed to the inoperative needles is cut by a fixed cutter co-operatingwith a rotary toothed cutter rotatable with the needle cylinder of theknitting machine which rotary toothed cutter also serves to catch saidyarn feed for said cutting.
 9. The method of knitting a plurality ofbrief blanks according to claim 6, wherein the yarn feed to theinoperative needles is trapped by means of a suction device.
 10. Themethod of knitting a plurality of brief blanks according to claim 6,wherein the fixed cutter is spring loaded against a face part of therotary cutter containing the cutter teeth thereof for obtaining aneffective yarn cutting action.